Having dabbled in the diesel turbo world I will tell you what I know (what I’ve been told) to the truthfulness and accuracy I can not attest.

Turbo lag is caused by an exhaust housing that is too large for the amount of exhaust gasses exiting engine, thus causing a longer time to spin the boost wheel causing the lag between the foot to the floor and the turbo catching up.


Exhaust housings that are too small are also an issue. We used to take the 20mm exhaust side housing off our hx35’s and put on 16mm ones. There were also 12’s but we found this caused exhaust temps higher than desirable without water injection to keep the pistons in it.


I’m sure there is a YouTube video somewhere that explains it in better detail.

https://youtu.be/5bGLcoSU73I